As a process for producing L-glutamine by fermentation, a method which involves a coryneform bacterium provided with azaserine resistance (cf. Patent Reference 1), a method which involves a coryneform bacterium provided with 6-diazo-5-oxo-norleucine resistance (cf. Patent Reference 2) and the like are known. In addition, as a process for producing L-glutamine by reinforcing glutamine synthetase activity, methods which involve a coryneform bacterium having reduced glutamine synthetase-adenylyl transferase activity which is controlled by adenylylation (cf. Non-patent reference 1, Patent Reference 3), and a coryneform bacterium in which an amino acid at position 405 of glutamine synthetase which is subjected to adenylylation is substituted and a coryneform bacterium having decreased activity of PII protein (cf. Non-patent Reference 2, Patent Reference 3) are known.
It is known that, in addition to glnA which encodes a glutamine synthetase, glnA2 which encodes a glutamine synthetase 2 having homology with glutamine synthetase is present on the genome of coryneform bacteria. It was reported that the polypeptide encoded by glnA2 of a coryneform bacterium has high homology with a glutamine synthetase of Bacillus subtilis which is not controlled by adenylylation, but the coryneform bacterium shows glutamine auxotrophic phenotype when glnA encoding a glutamine synthetase which is controlled by adenylylation is deactivated (cf. Non-patent Reference 1). In coryneform bacteria, the polypeptide encoded by glnA2 does not have glutamine synthetase activity, and there are no cases so far in which L-glutamine was produced by modification of glnA2.
In addition, it was reported that in Corynebacterium glutamicum, glutamic acid is produced by reduction of activity of a polypeptide which is encoded by ItsA and concerned in lysozyme sensitivity (cf. Non-patent Reference 3, Non-patent Reference 4, Patent Reference 4).    Patent Reference 1: Japanese Published Unexamined Patent Application No. 148094/80    Patent Reference 2: Japanese Published Unexamined Patent Application No. 232497/91    Patent Reference 3: Japanese Published Unexamined Patent Application No. 300887/02    Patent Reference 4: WO 00/14241    Non-patent Reference 1: FEMS Microbiology Letters, 201, 91 (2001)    Non-patent Reference 2: FEMS Microbiology Letters, 173, 303 (1999)    Non-patent Reference 3: BMC Biotechnol., 1, 9 (2001)    Non-patent Reference 4: Journal of Bacteriology, 182, 2696 (2000)